Rare earth luminescent material has become an important class of optoelectronic materials. In recent years, with the development of high-definition displays such as CRT, PDP, FED, etc., the requirement on the morphology of the phosphor has become increasingly high. It is usually considered the phosphor exhibiting a uniform particle size distribution, distribution of monodisperse, non-reunion, and spherical has a better application performance, because this type of phosphor has advantages such as high packing density, low light scattering, high resolution, and high brightness.
In considering of that, various methods have been developed to optimize the morphology of the phosphor. For example, urea was used as precipitant to prepare (Y, Tb)2O3 by coprecipitation so as to obtain a spherical phosphor with uniform particle size distribution. However, this spherical phosphor needs to use higher amounts of rare earth raw materials, thus increasing the manufacturing costs, so it is not suitable for industrial mass production and can not meet the wide range of application needs of the lighting display.
Nowadays, the preparation of dual core-shell fluorescent materials has become an important research focus in the field of luminescent materials. As for commercialization, the luminescent properties of obtained core-shell red fluorescent material is not ideal so far, and the luminous intensity needs for further improvement. For example, a SiO2@(Y, Eu)2O3 phosphor is designed and prepared according to core-shell structure theory using (Y, Eu)2O3 to coat SiO2. The phosphor can save the amount of the rare earth element. However, the prepared SiO2@(Y, Eu)2O3 phosphor has a low luminous intensity, resulting in that it cannot achieve industrialization.